1. Field of the Invention
The invention relates to a lamp device which is worn on or directly in front of the forehead, respectively, or above or beside the eyes, respectively, e.g., for medical applications in order to illuminate an area of treatment, comprising an integrated energy supply device, characterized in that several non-thermal, light-emitting elements are provided as a light source and that the individual light-emitting elements emit the light in a defined direction of radiation and are located in such a way that the light which is generated is directional.
The subject matter of the invention is a lamp which is worn on or directly in front of the forehead, respectively, or above or beside the eyes, respectively, and which ensures that the wearer""s freedom of movement is neither restricted nor hindered by cables or other connections. Such a lamp is intended, e.g., for medical applications in order to illuminate the area of treatment during diagnosis or treatment. However, the lamp is also usable for non-medical applications involving similar problems of illumination.
2. Description of the Related Art
Lamps and lamp devices worn on the head were designed in various embodiments, in particular for medicine. Thereby, the light is generated either a) directly in front of or on the head of the wearer, or b) in an external light source and is conducted via light guides made of glass, a synthetic material or a liquid to the side of the wearer""s forehead. In case of b), the wearer""s freedom of movement is more or less hindered or restricted, respectively, by the optical cable, and the weight of the light guide creates an unpleasant drawing stress leading to muscle strains in the back of the neck, to headaches or to other premature symptoms of fatigue. In case of a), cable-free sources of energy, which allow the wearer to move unrestrictedly, are indeed also used but the light sources used are of a thermal nature, which leads to a substantial heat development in front of and above the wearer""s forehead. Furthermore, the process of light generation takes place with small efficiency so that the packages of accumulators or the batteries, which usually are used, are relatively heavy, which again leads to the above-mentioned symptoms of fatigue. In addition, the light coming from the thermal light sources must first be concentrated by means of suitable optical instruments, which causes those headlamps to have relatively large weights and inconvenient dimensions.
It is the object of the invention to avoid the above-described insufficiencies of conventional headlamps, and the invention is characterized in that several non-thermal, light-emitting elements are provided as a light source and that the individual light-emitting elements emit the light in a defined direction of radiation and are located in such a way that the light which is generated is directional. Thus, it is advantageous that
1. the generation of light occurs directly on the head, i.e., in front of the forehead, above the eyes or besides the eyes of the wearer, by means of non-thermal, light-emitting elements. Preferably, those light sources are designed as light-emitting semiconductors whose radiation is modified such that the human eye receives an impression of white light. On the one hand, that guarantees high efficiency during the transformation of electric energy into light, and, on the other hand, the radiation of light is strongly directional, due to the mode of action and the structure of those light-emitting semiconductors. That directionality of the radiated light is utilized in the present invention, that is, in so far as:
2. several of those light-emitting elements are used, which
3. are located in such a way that the direction of radiation of each individual light-emitting element forms an angle with the visual axis of the wearer in such a manner that the center axis of radiation of all light-emitting elements has a common intersection point on the plane of symmetry of the wearer""s eyes at the desired monitoring or working distance, respectively, and
4. the distance of the individual light-emitting elements to that common intersection point is equal for all elements, and furthermore
5. the light-emitting elements are mounted such that the wearer may adapt the level of position of the illumination field generated in accordance with items 2 to 4 to his monitoring or working requirements, respectively.